Slag steam-generator.



H. MITCHELL. SLAG STEAM GENERATOR.

(Application filed Feb. 26, 1902.)

(No Model.)

Patented Oct. l4, I902.

3 Sheets-$haat IJ i" 4 "I H i i i i Q 57 1 i=1 i s i I i I 6 i I F k F WITNESSES 7a 1n: NORRIS PETERS 90,. PHOTO-LUNG wAsHmoTonA n. c

INVENTOR Patented Oct. 14, I902.

a. MITCHELL. SLAG STEAM GENERATOR.

(Application filed Feb. 26, 1902.)

3 Sheets-Shoet 2.

(No Model.)

26- f 1 [N VEN T OR 44.

WITNESSES m: uonms vnsas co. movoumo WASNINGTON, q. c.

No. 7||,33l. Patented Oct. 14, 1902.;

G. MITCHELL.

SLAG STEAM GENERATOR.

(Application filed Feb. 28, 1902.)

(No Model.) 3 Sheets-Sheet 3.

I z inf-33 23 20 in IglTNESSES m: Mcnms PETERS cofvnova-urhou WASHINGTON. 0. c4

UNITED STATES PATENT OFFICE.

GEORGE MITCHELL, OF NACO, ARIZONA TERRITORY, ASSIGNOR OF ONE HALF TO L. D. COPELAND, OF LOS ANGELES, CALIFORNIA.

SLAG STEAM-G EN ERATOR.

SPECIFICATION formingpart of Letters Patent N o. 71 1,331, dated October 14, 1902.

Application filed February 26, 1902. Serial No. 95,784. (No model.)

To all whom it may concern:

Be it known that I, GEORGE MITCHELL, of Naco, in the county of Cochise and Territory of Arizona, have invented certain new and useful Improvements in Slag Steam-Generators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Myinvention relates to an improvement in slag stea1n-generators, and has for its object the production of an apparatus of such construction that the heat units contained in slag or other refuse material produced in a blast or other furnace converter or metallurgical apparatus maybe utilized in generating steam for use in operating steam-engines or other purposes.

2o \Vith this object in view the invention consists in certain features of construction and combinations of parts, as will be hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure l represents a view, partly in vertical section and partly in side elevation, of one embodiment of myinvention. Fig. 2 is a similar view of another embodiment of the invention, in which only one steam-generator is employed.

0 Fig. 3 is a view similar to Fig. 2, except that it is taken at right angles thereto. Fig. 4 is a plan view. Fig. 5 is a transverse section of the oscillating valve and the lower end of the slag-feeding chute or receptacle, and Fig. 0' is 5 a longitudinal section of the same.

1, 2, and 3 represent a series of steam-generators connected together. The shell of each generator may be made of boiler-iron or steel and of any desired shape, although I prefer to make it of a cylindrical body portion 5, a rounded top (5, and funnel-shaped bottom 7, substantially as is represented in the drawings. Each one of the steam-generators is provided with a manhole 8 of the required 5 size and shape to permit of ready access to the interior of the shell.

9 represents detachable cast-iron lining-sections removably secured within the funnelshaped bottom section 7, and 10 represents similarcast-ironlining-sections removablysecured within the lower portion of the main shell 5. The object of these detachable linings is to shield the outer shell of the generator against undue wear, to which it would otherwise be subjected by the friction of the slag against its inner surface as it is fed through the generator. When the linings become unduly worn, they may be readily removed and replaced by new lining-sections.

The top of steam-generator l is constructed with a central opening 11, around which is secured a flange 12. To the latter is removably fastened the outwardly-projectiug flange 13 on the lower section 14 of a feed chute or conduit. The lower end of the feed-chute extends downwardly into the main shell of the generator and is provided with an outwardlyflaring ground orsmooth valve-seat 15,against which is seated the oscillating valve 16.

Rock-shaft 17 extends through the shell of the generator and also a stulling-box 18, attached thereto. The inner end of the rockshaft may be supported by a depending bracket fastened to the top of the generator, or, if desired, both ends may extend through stuffing-boxes attached to the shell. A handle 19 is secured to one end of the rock-shaft, by means of which the rock-shaft and oscillating valve 16 may be actuated. The inner end of the rock-shaft is constructed with a square or angular section 20, on which is mounted the oscillating valve 16, the opening 21 in the latter being larger than the rock-shaft, so as to permit the valve to beadjusted toward or from its seat 15. The valve is furnished with any desired'number of-cylindrical pockets 22, in each of which is inserted a spiral spring 23, which are inserted in place through openings 24, provided with screw-plugs 25 for retaining the springs in place. The lower end of each 0 one of the springs is seated upon the square face .of the rock-shaft, While its upper end bears against a vertically-movable block 26, having an inclined upper face 27, with which engages a transversely-adjustable wedge 28, having screw-threaded extensions 29, with which engage the nuts 30. By adjusting these wedges the valve may be forced against its seat under any desired tension of the springs 23, and hence the wear of the valve or valve-seat can be readily compensated for and a steam-tight joint maintained. Each end of the valve-hub is provided with a transverse slot 31, within which fits a wedge 32, which passes through the rock-shaft and may be secured against displacement by means of a pin 33. These wedges secure the valve to the rock-shaft in such manner that the valve will be oscillated thereby and will be permitted a free adjustment to compensate for wear and also to yield sufficiently to prevent its becoming unduly obstructed or its operation impaired.

Feed-chute section 14 is made outwardly flaring from its upper to its lower end in order to insure a free feeding action and dis-- charge of the slag that is fed into and through the chute. The upper section 34 of the feedchute constitutes the casing of a rotary valve and is provided at its upper end with a hopper 35, into which the hot slag is fed. Section 34 of the feed-chute is constructed with detachable sides 36, one of which has attached thereto a stuffing-box 37 and gland 38 for tightly packing the shaft 39 of the rotary valve. The outer end of the valve-shaft is supported by a bracket 40 and is provided with a handle 41. Within the valve-casing is located a rotary valve 42, having a large through opening or passage 43, which on being adjusted to register with the openings 44 and in the upper and lower ends of the casing 34 will allow the hot slag deposited in the hopper to feed by its gravity through the valve and into the lower chute-section 14, wherein the slag is supported by the oscillating valve. By rotating the valve 42 so that its solid portions cover the openings 44 and 45 the feeding of the slag is prevented, as well as the escape of steam from the lower section of the feed-chute.

To prevent the hot slag from sticking in and obstructing its feed through the lower section of the feed-chute, I provide means for dislodging any such obstruction, which are constructed and operated as follows: 46 is an oscillating drift-bar or hook secured at its upper end to a rock-shaft 47, supported in bracket-bearings attached to the under side of the top of the shell of the generator. 48 is a rock-shaft which extends through the generator-shell and also through a stuffing box and gland 49 50andis provided at its outer end with a handle 51, by which it is actuated. Rockshaft 47 has an arm 52 rigidly secured thereto, and a similar arm 53 is secured to rock-shaft 48. These two arms are connected by a link 54. When the drift-bar or hook 46 is not in use, it is locked in the position shown by full lines in Fig. 1, and in such position it cannot interfere with the operation of the oscillating valve or with the feeding of the slag. The lock is effected by and is due to the relative positions of the arms 52 53 and link 54. When it is desired to dislodge any slag that has stuck or become lodged in the feed-chute, the lever 51 is turned, which has the efiect of breaking the lock and raising the drift-bar or hook into the position shown in dotted lines, thereby causing it to engage and dislodge any slag that may have become stuck or lodged in the feed-chute, and when the drift-bar or hook is in this position the arms 52 53 and link 54 will be in the position indicated by the dotted lines. By releasing the handle or lever 51 the weight of the drift-bar or hook will operate to cause the parts to resume their original and locked position.

A steam-pipe 55 communicates with the upper portion of steam-generator 1 and serves to convey a supply of steam to any point desired for use.

56 is an ordinary safety-valve.

57 is a globe-valve for closing or opening the steam-pipe 55. A steam-gage 58 may be attached -to steam-pipe 55, or it may be connected with the generator. A check-valve 59 is located in steam-pipe 55, so that in the event the pressure in the steam -generator should fall below the pressure in the boiler or battery of boilers with which it is connected the back pressure from the boilers will operate to close the check-valve and maintain it closed until the pressure in the generator exceeds the pressure in the boiler or battery of boilers to which steam is supplied, and then the check-valve will be opened. In this way the pressure in the boiler or battery of boilers may be maintained practically uniform.

A steam-pipe 6O communicates at one end with the steam-space of steam-generator 1 and at its other end with the feed-chute. Interposed in this pipe is a three-way valve 61 for opening and closing communication between the steam-generator and feed-chute and also for permitting of the escape of steam from the feed-chute through pipe 62 to the open air, feed-water tank, or other desired point.

To the lower end of the funnel-shaped section of steam-generator 1 is secured a flanged ring 63, to which is attached the upper end of a rotary-valve casing 64, in which is disposed a rotary valve 65. The valve-casing is constructed with detachable side sections and is provided with a stuffingbox and gland 66 67 for packing the valve rod or shaft 68. A handle 69 is attached to the shaft for actuating it and the valve. Steam-generators 2 and 3 are connected in series with steam-generator 1, and each is constructed and provided with an oscillating valve and the several appliances already described in connection with steamgenerator 1. v

To the lower and discharge end of steamgenerator 3 is connected a steam and water chamber 70. A pipe 71 leads from this chamber to a feed-water tank in order that the heat contained in the steam and water that I as represented in Figs. 2 and 3.

discharge end of chamber and is actuated by a hand-wheel 73. If desired, a rotary valve may be used instead.

Steam-pipes 74 and 75 communicate, respectively, with the steam-space in the upper portions of steam-generators 2 and 3 and convey the steam generated therein to the same or to separate boilers or batteries of boilers.

Each one of the steam-generators is provided with a water-jacket 76, which serves to protect the shells of the generators and also to collect the heat radiated therefrom and store it in the water contained in the jacket. Ihese waterjackets may be connected together by pipes 77, provided with suitable valves for cutting off either one of them when desired.

78 represents a feed-water pipe through which water is supplied to the several waterjackets by any suitable feed-water pump, and 79, 80, and 81 represent independent pipes through which the heated water from the Water-jackets is supplied to the generators or to a feed-water tank, as may be desired. Each one of the generators may be supplied with an ordinary water-glass 82 for indicating the amount of water in each generator, and each may be furnished with a steam safety-valve.

While I have described three of my improved slag steam-generators arranged in series to permit the hot slag to be fed successively into and through them, it is evident that I may employ only two of the generators connectedin series, and excellent results are obtained by the employment of only one,

While I prefer to employ a water-jacket, still it is not essential to my invention and may be dispensed with, as in the construction of generator represented in the last-named figure. Again, while I have represented eachone of the steam-generators as being provided with an oscillating valve and means for dislodging the slag from the feeding-chutes I do not restrict myself to the employment of all these devices in each one of the generators, as it maybe found desirable in practice to dispense with some of them.

Having described the construction and arrangement of parts of my improvement, I will now explain its mode of operation in connection with the embodiment of the invention represented in Fig. 1. Each one of the steam-generators 1, 2, and 3 is partly filled with water, and thewater-supplv to their jackets is maintained by any suitable feed-water pump. At the outset all of the valves are closed. Hot slag is fed into the hopper 35, and by opening the rotary valve 42 the slag is fed by its gravity into the feed chute or chamber 14, in which it is supported by the oscillating valve 16. The three -way valve 61 is then operated, so as to permit steam to flow from generator 1 into the upper end of the feed-chute 14, in which the hot slag has been fed, and thereby cause the steam-pressure in the feed-chute to be equal to the steam pressure in 'the generator. The oscillatiugvalve 16 is then opened and the charge of hot slag supported thereon is fed by gravity into the body of water in generator 1, with the effect of imparting part of its heat thereto and generating steam. The admission of steam into the upper portion of the feed-chute 14 and above the charge of hot slag contained therein has the eltect of assisting and hastening the feeding and expulsion of the slag from the feed-chute into the generator, owing to the fact that the instant steam is admitted into contact with the hot slag it is at once superheated and expanded, and being confined in a small space its pressure will be raised so suddenly that on opening valve 16 the downward pressure of steam on the charge of slagwill assist in forcing the latter downwardly and into the body of water in the generator. In order to prevent the hot slag from sticking to the sides of the feed-chute, the latter is gradually enlarged from top to bottom, so as to insure a free discharge of the slag therefrom. In the event any slag should accidentally become stuck or clogged in the feed-chute it may be readily dislodged by means of the curved drift-bar or book in the manner already explained. After a charge of slag has been fed into generator 1 its valve 16 is closed and also the three-way valve 61 is actuated, so as to cut 06 the supply of steam to the feedchute and to permit steam to escape therefrom into the open air or a feed-water tank, as may be desired. The charge of hot slag falls into the water contained in steam-generator 1 and imparts part of the heat stored therein to the water, a portion of which is quickly converted into steam. The direct and intimate contact of the hot slag with the water-supply in steam-generator 1 not only serves to rapidly extract heat from the slag, but also operates to granulate the latter, which collects in its granulated condition in the'funnel-shaped lower section of the generator. When a sufiicient amount of granulated slag has accumulated in the lower part of generator 1, the rotary valve 42, located in the feed-chute interposed between steam-generators 1 and 2, is opened and the charge of granulated slag is fed into the chute 14 and is therein supported by the oscillating valve 16 in steam-generator 2. The rotary valve 42 is then closed. In feeding the slag from generator 1 into generator 2 a small quantity of hot water and steam will also be fed into the feed-chute 14; but the amount will be small, owing to the fact that the capacity of feed-chute 14 is only slightly greater than is necessary to hold the chargeof granulated slag, and hence only a comparatively small quantity of water and steam will escape from generator 1 into generator 2 as the slag is fed successively through them. The manipulation of generator 2 ispl'ecisely the same as that of generator 1. After a charge of granulated slag has accumulated in the bottom of generator 2 it is then fed into generator 8 in the manner and with the effect already described. Should it be found that grannlated slag tends to cake in the bottom of the generator, and thereby obstruct or interfere with its free feeding action, the difficulty may be readily remedied by providing a suitable rotary stirrer in the lower end of each generator, which on being actuated will quickly break up the slag and cause it to feed freely. The slag accumulating in the bottom of generator 3 is discharged into the chamber 70, and the heat contained in the small quantity of hot water and steam that escapes into the chamber when a charge of slag is fed into it is utilized to heat the feed-water supplied to the generators, the hot Water and steam being conveyed from their chamber through pipe 71 to the feed-water tank. The granulated slag that is collected in chamber is discharged therefrom from time to time through the globe-valve 72. The steam generated in the apparatus may be conveyed through steam-pipe 55 to any desired point for use, in which case the steam-pipes 74 and 75 will be connected with pipe 55, or, if desired, the steam generated in each one of the generators may be conveyed to separate and independent boilers or batteries of boilers. The heat radiated from each steamgenerator is utilized to heat the water contained in the water-jackets, and the water thus heated may be conducted to a feed-water tank, from thence supplied to the generators.

While I have shown three steam-generators connected in series, I may employ any desired number, and in some cases may use a single generator, as represented in Figs. 2 and 3.

It will be noted that the construction and mode of operation of the apparatus is such that the force of gravity is utilized for feeding the slag through the apparatus, provision being made for regulating and controlling the feed in such manner that all or practically all of the heat units contained in the slag are utilized to generate steam,while the hot slag is transformed into a granular condition, which facilitates its subsequent handling and disposition. By the employment of several generators connected in series the hot slag may be fed into the upper generator while the cool slag is being discharged from the lowermost generator of the series, and thus the process may be a continuous one.

The invention is of great value and importance in all metallurgical operations which involve the production of hot slag or other heated refuse or material, because it enables practically all the heat units stored in the slag or refuse to be utilized at comparatively little expense to generate steam which may be utilized for operating steam-engines,blowe1*s, pumps, or other purposes, and it is especially valuable for use at points distant from sources of coal or fuel supply and where the cost of fuel is excessive.

I make no claim herein to the improved method herein described fol-generating steam from hot slag, as it constitutes the subjectmatter of a separate application filed January 24:, 1902; but,

Having described my improved slag steamgenerator, What I claim herein as new, and desire to secure by Letters Patent, is-

1. In a slag steam-generator, the combination with a steam-generator provided with a removable sectional lining, ofmeans for feeding slag into the water contained in the generator, means for discharging the slag from the lower portion of the generator, and means for maintaining the pressure within the generator while slag is being fed into and discharged from the same, substantially as set forth.

2. In a slag steamgenerator, the combination with the steam-generator and feed-chute, of an oscillating valve engaging the lower end of the chute and constructed to have a yielding engagement with its seat, substantially as set forth.

3. In a slag steam-generator, the combination with the steam -generator, feedchute, and rock-shaft extending through the generator and provided with an actuating-handle on its outer end, of an oscillating valve yieldingly mounted on the rock-shaft and means for regulating its adjustment with reference to the valve-seat on the feed-chute, substantially as set forth.

4. In a slag steam-generator, the combination with the steam-generator, feedchute, and rock-shaft, of an oscillating valve mounted on the rock-shaft, springs interposed between the rock-shaf t and valve, and means for adjusting the tension of the springs, substantially as set forth.

5. In a slag steam-generator, the combination with the steam generator, feed chute and rock-shaft, of an oscillating valve mounted on the rock-shaft, springs for holding the valve in yielding engagement with its seat, and means for securing the valve to the rockshaft so as to cause it to be actuated thereby and still permit it to be adjusted toward and away from its seat, substantially as set forth.

6. The combination with a steam-generator, a chute for feeding slag into the water contained in the generator, and a valve at the lower end of the chute for regulating the discharge of slag therefrom, of an oscillating hook or drift bar, means for moving it into and out of the lower end of the chute, and means for automatically looking it out of use, substantially as set forth.

7. In a slag steam-generator, the combination with a steam-generator and slur-feeding. and through each one of said stean1-generachute, of a rock-shaft having a drift-bar or tors, substantially as set forth.

hook secured thereto, a rock-shaft provided In testimony whereof I have signed this with a handle, and arms and a link for conspecification in the presence of two subscrib- 5 necting the two rock-shafts, substantially as ing Witnesses.

set forth.

8. In a slag steam-generator, the ooinbinai GEORGE MITCHELL tion with two or more water-jacketed steain- Vitnesses: generators connected in series, of means for FRANK J. NICHOLS,

:o feeding charges of hot slag successively into MARGARET KNIGHTLY. 

